1. Field of the Invention
The present invention relates generally to communications networking, and more specifically, to media access control processing within a communications network.
2. Related Art
In recent years, cable network providers have expanded the variety of services offered to their subscribers. Traditionally, cable providers, for instance, delivered local and network broadcast, premium and pay-for-view channels, and newscasts into a viewer's home. Some modern cable providers have augmented their portfolio of services to include telephony, messaging, electronic commerce, interactive gaming, and Internet services. As a result, system developers are being challenged to make available adequate bandwidth to support the timely delivery of these services.
Moreover, traditional cable broadcasts primarily require one-way communication from a cable service provider to a subscriber's home. However, as interactive or personal television services and other nontraditional cable services continue to strive, communications media used to support one-way communications must now contend with an increased demand for bi-directional communications. This results in a need for improved bandwidth arbitration among the subscribers' cable modems.
In a cable communications network, for example, a communications device (such as a modem) requests bandwidth from a headend device prior to transmitting data to its destination. Thus, the headend device serves as a centralized point of control for allocating bandwidth to the communications devices. Bandwidth allocation can be based on availability and/or competing demands from other communications devices. As intimated above, bandwidth typically is available to transmit signals downstream to the communications device. However in the upstream, bandwidth is more limited and must be arbitrated among the competing communications devices.
A cable network headend includes a cable modem termination system (CMTS) which comprises a media access controller (MAC) and central processing unit (CPU). The MAC receives upstream signals from a transceiver that communicates with remotely located cable modems. The upstream signals are delivered to the CPU for protocol processing. The protocol processing is conventionally defined by the Data Over Cable Service Interface Specification (DOCSIS™) for governing cable communications. Depending on the nature of the protocol processing, the CPU must be able to handle these operations efficiently and timely as to not impede performance. As more subscribers and/or services are added to the network, greater emphasis is placed on the MAC and CPU to sustain protocol processing with no interruption in service.
Therefore, a system and method that increase packet throughput capacity and sustain performance are needed to address the above problems.